Altec Lansing Model 6 (1981)

Name: Altec Lansing Model 6
Brand: Altec Lansing

A three-way bookshelf speaker system with bass reflex design, released in 1981 and featuring Altec’s constant-directivity horn technology.

Overview

The Altec Lansing Model 6 is a three-way, three-speaker bookshelf system released in 1981, designed by Paul Supran Gar, Altec's top engineer. It was part of a line of more compact speaker systems that brought high-end horn technology—like the Tangerine radial phase plug and Mantaray constant-directivity horn—from larger professional models into a domestic format. The system features a 10-inch woofer, 5-inch midrange cone, and a piezoelectric compression driver using lead-zirconate titanate (LZT). It includes front-panel controls for adjustable midrange and high-frequency output, and incorporates a passive "Automatic Power Control" circuit that attenuates the signal during overload, indicated by a glowing red light.

Specifications

Type	Three-way system
Frequency response	60 to 20,000 Hz ±2.5 dB
Nominal impedance	8 Ω
Laboratory measured impedance	5 ohms in the 20- to 30-Hz region, peaking at 30 ohms at 60-Hz resonance, 7 ohms at 100 Hz, varied between 7 and 16 ohms over the rest of the audio range
Maximum impedance	17 ohms in the upper treble region
Rated sensitivity	90 dB SPL at 1 meter with 1 watt of wideband pink noise
Laboratory sensitivity measurement	87 dB with 1 watt input using an octave band of noise at 1,000 Hz
Recommended amplifier power	20 to 200 watts per channel
Continuous power handling	100 watts (28.3 volts into 8 ohms)
Peak power handling	400 watts (56.6 volts into 8 ohms) for peaks up to 117 dB SPL
Crossover frequencies	700 Hz, 5 kHz
Crossover type	Pass-band stable network
Drivers	10-inch woofer, 5-inch midrange cone, piezoelectric compression driver (LZT)
Woofer resonance	about 62 Hz
External dimensions	15-1/2 inches wide, 25-1/2 inches high, 13-1/2 inches deep
Weight	37 pounds
Cabinet finish	Glossy polish, Endriana wood veneer
Grille	Semitransparent black grille cloth
Input connectors	Spring-loaded, recessed into the rear of the cabinet
Controls	Continuously variable midrange and tweeter-level adjustment knobs on front panel
Midrange control range	Maximum cut of 15 dB at 2.5 kHz; up to 2 1/2 dB of boost at 2.5 kHz
High-frequency control range	About 7 dB of additional output above 8 kHz at maximum; gradual rolloff starting at 2.5 kHz, down approximately 7 dB or more above 8 kHz at minimum
Protection	"Automatic Power Control," a passive circuit that attenuates the signal during overload; a red light glows when activated
Warranty	Limited, five years parts and labor

Design

The Model 6 uses a bass reflex (ported) enclosure with a front baffle covered in black acoustic-damping material and flush-mounted drivers for reduced diffraction. The tweeter is a piezoelectric compression driver using lead-zirconate titanate (LZT), paired with Altec’s Tangerine radial phase plug and the computer-designed Mantaray constant-directivity horn, which can be rotated 90 degrees for horizontal placement. The "Automatic Power Control" is a passive, signal-powered circuit that activates under overload, protecting the drivers without external power.

Context

Released in 1981, the Model 6 was the three-way centerpiece in a series of more compact speaker systems from Altec Lansing, bringing horn-loaded high-frequency technology from professional models like the Model 19 into a domestic bookshelf format. It was designed to deliver flat frequency response, deep bass, and wide dispersion with low distortion, offering high performance at a fair market price of $350 at launch.